One time prepare & prepare in mass actions

* added $prepared attribute to indicate if prepare() was done
* if $prepared prepare() exits on begin

* processSessionData() and prepare() is always called (not only for actionAllKeys) in processMassActions() to enable accessing filtered grid data.
processSessionData fix

Fix according to "I think processSessionData must be call before page=0 and limit=0 to override these parameters when actionAllKeys is true"
Allow css class(es) to be added to rows similar to how we add apply an inline style to change the background.
Getter for entity name
Fix endline
Add column safe doc
Add global sortable with the source annotation
Updated the manager to use only one type of each driver per run, as they are inserted in -1 order the most recent one will be on top
Revert "Updated the manager to use only one type of each driver per run, as they are inserted in -1 order the most recent one will be on top"

This reverts commit 46d42fdbc7ec63296d2255c94ae480e64009edb6.
Merge branch 'master' of github.com:Abhoryo/APYDataGridBundle
Changed the scope grid.mapping.manager service to be prototype instead of
container as it can cause issues in its current form as container scope.
Also the benefit of having it in container scope are not clear.
Merge pull request #401 from daum/master

Move grid.mapping.manager service to prototype scope
Merge pull request #396 from darnel/patch-1

One time prepare & prepare in mass actions
Fix CS
Added group-by clause in ORMCountWalker to fix crash in Oracle. Also tested on MySQL.
Update Column.php
Merge pull request #402 from whachoe/master

Fix for Oracle
[Possible BC] Add the possibilty to filter on a hidden column in the extern search block

If you want to default filtered on an hidden column without display its filter, set filterable to false and of course visible = false.
Parse parent entity properties
Parse parent entity properties